BOTATOBIA OF THE UNITED STATES. 
319 
Antennce . — The dorsal antenna is situated in the dorsal furrow mentioned above, a little 
behind the constriction which separates off the head-sheath. The lateral antennas are in nearly 
the usual position on the posterior third of the body, hut the left antenna is considerably farther 
forward than the right. (Compare figs. 41 and 44.) 
Foot. — A short, thick joint, which can apparently be retracted within the lorica (see fig. 40). 
Toes . — There are two toes, very close together. The longer left toe is about half as long as 
the body of the animal, while the right toe is about two-thirds the length of the left (fig. 43). 
There are two minute substyles at the base of the main toes (fig. 43). 
Internal organs . — The prominent brain bears a large red eye at its posterior end. The trophi 
(fig. 42) are unsymmetrical, the right malleus being much reduced. 
Measurements. — Total length, 0.15 to 0.18 min., of which the toe forms about one-third. 
History. — This species has not been described before. It was drawn by Mr. Dixon-Nuttall 
some years ago, and copies of his drawing have been distributed to many workers on Rotifera under 
the name Ccelopus brctchyurus, but he agrees with me that this is not really the Ccelopus brachyu- 
rus of Gosse (see the account of Diurella brachyura) , so that it is necessary to give it a new spe- 
cific name. I name it therefore after the investigator who first figured it. The figures herewith 
presented (figs. 40-44) are all by Mr. Dixon-Nuttall, and my description is based upon them. 
Distribution. — This species has not been found in America. According to Mr. Dixon-Nuttall 
it is common in ponds in England. 
DESCRIPTIONS COMPILED FROM OTHER AUTHORS. 
13. Diurella sejunctipes Gosse (pi. xiv, figs. 120, 121). 
Synonym : Rattulus sejunctipes Gosse (1889) . 
Distinguishing characters. — “ Body projecting much above and behind the foot; toes, two, 
coequal v slender, decurved, set side by side, wide apart” (Gosse, 1889, p. 66). The body is said 
to be stout, plump, and curved; the foot is short and thick. Gosse described what is evidently 
the mucus reservoir as “ a great basal bulb, wholly internal,” forming part of the foot. The toes 
are two equal acute slender styles, so curved as to continue the outline of the body, and are wide 
apart at the base. The trophi were figured by Gosse “ conjecturally. ” 
Described by Gosse from notes by Dr. F. Collins. Found by the latter in a pool near Welling- 
ton Military College, Birks, England. 
Stenroos (1898) found this species in Lake Nurmijarvi, in Finland, and gave a figure (fig. 121) 
and measurements. Length of body, 0.109 mm. ; thickness, 0.03 mm. : length of toes, 0.03 mm. 
Distribution . — As above and in Bohemia (Petr, 1890). 
14. Diurella collaris Rousselet (pi. xiv, fig. 127). 
Synonym: Rattulus collaris Rousselet (1896). 
I give herewith Mr. Rousselet’s description of this species in his own words: 
“In shape the body is roughly cylindric, slightly curved behind; the lorica is finely pitted or 
stippled, giving it a roughened appearance; it has no dorsal ridge and is fairly stiff, except in the 
neck region, where the integument is more flexible and frequently forms a thickened collar when 
the animal is bending or retracting, and from this characteristic peculiarity the animal derives its 
specific name. The foot opening is oblique, nearly ventral, and the lorica overhangs the foot 
dorsally in a marked degree. The head is elongated, truncate in front, and somewhat tapering 
anteriorly, and it is furnished with a simple wreath of cilia; it contains a conical brain mass, with 
a red eye at the tip, and long jaws of the Rattulus type. The long, thin oesophagus is attached to 
a Diurella uncinata Voigt.— While this paper was passing through the press, Voigt published a brief diagnosis of 
a new species of Diurella , under the name Ccelopus uncinatus (Zoologisclxer Anzeiger, Bd. 25, 1902, p. 679). For the 
sake of completeness I append a translation of his description: “ Body short, curved. Anterior edge of the lorica 
slightly denticulate. Somewhat to the right of the middle line, when the animal is viewed from the dorsal side, 
ai'ises a long, rapidly narrowed, somewhat curved process. The short foot shows two unequal curved toes. Jaws 
unsymmetrical. A large x-ed eye-spot. Length of the body without the pi’ocess, 0.095 mm. Length of the largest 
toe 0.02 mm. Length of the frontal process, 0.027 mm. Occui-rence: November, 1900 and 1901 in the Schluen-See and 
Schoh-See, amid Potamogeton and Phragmites. Specimens few.” 
The diagnosis is not accompanied by a figure. A full description, with figures, is promised for the forthcoming 
(ninth) Heft of the Forschungsberichte aus der Biol. Station zu Plon. 
